There are not many commercial coatings available for corrosion resistance at high pressure and high temperature with multiphase flow in the presence of sweet and sour gas. Sour gas is any gas, but often natural gas, containing significant amounts of H2S. Thus, such conditions are commonly encountered in oil and gas drilling and exploration operations. Deep sea and land oil and gas drilling typically involve pipeline temperatures of 200-250° C. and pressures above 100 psi and up to 20000 psi.
Corrosion resistant alloy coatings are difficult to apply on the interior of pipelines and in inaccessible areas and the process is not scalable. Existing corrosion resistant coating technology lacks H2S and CO2 corrosion resistance. Most of the commercial solutions are based on a polymer or composite coating to prevent corrosion and H2S/CO2 attack but they provide minimal protection once the coating is damaged. The use of polymer-based coatings only provides a temporary resistance to these gases which is not maintained at high pressure and temperature.
Needs exist for improved corrosion-resistant surface treatments and coatings for use in the presence of sweet and sour gas and at high temperatures and pressures.